Kansas LTAP Fact Sheet

A Service of The University of Kansas Transportation Center for Road & Bridge Agencies

Save Electricity with LED Streetlights By Nora Fairchild

f you are trying to make sustainable including solar-powered. Using solar changes in your community, one power is especially feasible for these Isimple solution is to install or fixtures because the energy draw from replace existing street lights with LED LED bulbs is much lower than for light fixtures. This article will explain incandescent bulbs. how LEDs work, the costs and benefits Can be retrofitted. A new LED unit of making the switch and how LED can replace an incandescent unit on an lighting contributes to sustainability. existing pole. Swapping the units takes only about 30 minutes per fixture, per How LED lights work differently the Missouri S&T. than incandescent bulbs Light-emitting diode (LED) light Cost bulbs are becoming fairly common Upfront, LED street light units in household use. Due to their LED bulbs are valued are significantly more expensive than energy efficiency and long-term cost- for their potential 93 traditional ones. According to an effectiveness, communities are bringing percent energy savings article in USA Today, LED units cost the bulbs to a larger scale for use in street about $1000 per unit compared to light fixtures. and 10 year lifespan. conventional units that are around $250 The fixtures include many each. Bulbs are more expensive too; individual LED bulbs in one unit. The LED street light bulbs themselves go light from LED bulbs is clear blue for about $40, while conventional high or white rather than yellowish like pressure sodium lamp bulbs are about incandescent street lamps. This change mercury and produce less heat than other $20. However, LEDs are much more helps colors being illuminated to look bulbs so that the unit can work efficiently energy efficient, and that’s the primary more “true,” and may help some people without premature bulb burnout. LED way long-term cost savings are achieved. see better while driving. bulbs transfer heat over the area of the While communities would have to pay lamp evenly, and the unit lasts longer more for the fixture to start, they would Efficient and effective as a result. Missouri S&T estimates the save maintenance costs and energy costs Several characteristics of LED lifespan of an LED bulb at 10 years. over the long run, helping to make up fixtures help communities save money: Maintenance advantages. While the difference. Energy efficiency. LED fixtures traditional bulbs need to be replaced as use significantly less power to operate soon as the bulb goes out, LED fixtures Communities using LEDs than incandescent fixtures. According contain many small individual bulbs Many communities across the United to a study by the Missouri Center for that create a uniform glow so it is hardly States, large and small, are using or Transportation Infrastructure and Safety noticeable when a few of the small bulbs piloting LED street light fixtures in their at the Missouri University of Science go out. Maintenance can be scheduled at jurisdictions. Here are just a few: and Technology (Missouri S&T), regular intervals rather than in response City of Los Angeles, California, LEDs can provide a 93 percent energy to instances of street lights burning out. uses LED street lights, and their Bureau savings. A good fit with solar power. LED of Street Lighting states that LEDs are a Bulb longevity. LEDs contain no light fixtures come in different types, no-cost sustainable alternative because

Kansas LTAP Fact Sheet Page 1 industry. Because the products are so ccording to Pacific Gas and Electric Company there are many benefits of new, variations of LEDs fixtures come Areplacing traditional street light bulbs with LED bulbs: out often that you may not be able to • Improved night visibility for pedestrians, bicyclists and drivers due to higher depend on using the same replacement color rendering, higher color temperature (more prevalence of yellowish equipment and bulbs and procedures white, orange and red colors) and increased illuminance uniformity again and again. • Significantly longer lifespan Very bright light. According to • Lower energy consumption the Missouri S&T, there have been • Reduced maintenance costs complaints that LED street lights are • Instant-on with no run-up or re-strike delays too bright and at times distracting for • No mercury, lead or other known disposable hazards drivers. In residential areas, LED street • Lower environmental footprint lights can be bothersome at night • An opportunity to implement programmable controls (e.g. bi-level lighting) when they are in close proximity to bedroom windows. However, Meredith says that the complaints he received in Riley County were that the solar lights they are highly efficient. capacity for power. The streetlight also installed in their parking lot were not City of Lawrence, Kansas. A remains dim until a car approaches, bright enough. He plans to install one newspaper article about Lawrence, preserving power until it is needed. of the brightest LED fixtures soon to Kansas’ switch to LED bulb units in the LEDs do not take as long as traditional compare it to the relatively dimmer vintage-looking streetlights downtown lights to illuminate to full brightness. models he currently has in place. reported that it will take about 40 years These units cost about $7,000. On the plus side, LEDs’ capacity for for the lights to pay for themselves in Meredith says solar technology brightness could allow bicyclists to ride energy savings. Even with the long coupled with LED fixtures really saves at night with greater safety. payback, staying with traditional bulbs money if the fixtures are being placed in may soon not be an option for many a new area that would otherwise not need Are LED units worth the extra cost? communities. Assistant city public works electrical lines installed. The initial cost of LEDs can director Mark Thiel said Lawrence’s Riley County plans to install three be intimidating and could deter a switch to LED lights would be inevitable more types of LED street lights in their community from making the switch. because of decreasing production and parking lot this year to consider the However, LED street light fixtures are decreasing popularity of metal halide best options for future use in parks and energy-efficient and can be cost-effective and high pressure sodium light bulbs. possibly on county roads. Meredith says in certain situations. They have more Riley County, Kansas. Riley County that the LED street lights they are testing potential to be cost effective for new Public Works has installed five different are self sufficient and work well. installations rather than retrofits on types of LED street lights in their For more information about Riley existing fixtures that already have an parking lot to test their effectiveness. All County’s test of solar powered LED incandescent fixture in place and you are solar powered. units, contact Rod Meredith at could just continue replacing the bulb Solar panels come in two types— (785) 539-2981. when it burns out. Still, retrofits allow monocrystalline and thin film. Rod for significant energy savings and more Meredith, the County’s assistant public Potential downsides to using LED predictable maintenance—a plus for works director, says the thin film system technology any community, and something to is a better alternative for use with LEDs Technology is new and changing. consider as electricity prices continue because it includes batteries in the base Meredith said the only thing to watch to rise in Kansas and the availability of of the pole that enable more storage out for is the rapidly changing LED incandescent bulbs declines over time. ■

Reprinted from the Summer 2011 issue of the Kansas LTAP Newsletter, Sources: a publication of the Kansas Local • Grassman, Scott E. et al. “Alternative Energy Sources for MoDOT.” Missouri Technical Assistance Program (LTAP) S&T. February 2011. http://ntl.bts.gov/lib/36000/36000/36022/R260_CR.pdf at the Kansas University Transportation • Metz, Christine. “Downtown Street Lights Switched to LED.” Sunflower Horizons. Center. May 31, 2011. http://sunflowerhorizons.com/groups/making-good-choices/2011/ may/31/downtown-street-lights-switched-to-led/ • Lunar Accents Design. “LED Thermal Management” 2008. http://www.lunaraccents.com/educational-LED-thermal-management.html • Email and phone interviews with Rod Meredith and Mark Thiel, 2011.

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